CVE-2026-28435

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, cpp-httplib (httplib.h) does not enforce Server::setpayloadmax_length() on the decompressed request body when using HandlerWithContentReader (streaming ContentReader) with Content-Encoding: gzip (or other supported encodings). A small compressed payload can expand beyond the configured payload limit and be processed by the application, enabling a payload size limit bypass and potential denial of service (CPU/memory exhaustion). This vulnerability is fixed in 0.35.0.

Database specific

{
    "cwe_ids": [
        "CWE-400",
        "CWE-409"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28435.json",
    "cna_assigner": "GitHub_M"
}

References

Affected packages

Git / github.com/yhirose/cpp-httplib

Affected ranges

Type

GIT

Repo

https://github.com/yhirose/cpp-httplib

Events

Introduced

Fixed

85b18a9c6431877188a706ba3c61679fa9de3e27

Fixed

c99d7472b5cf4869d3897b9afc9792063a3d15a8

Database specific

{
    "cpe": "cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*",
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.35.0"
        }
    ]
}

Affected versions

Other

latest

v0.*

v0.10.0

v0.10.1

v0.10.2

v0.10.3

v0.10.4

v0.10.5

v0.10.6

v0.10.7

v0.10.8

v0.10.9

v0.11.0

v0.11.1

v0.11.2

v0.11.3

v0.11.4

v0.12.0

v0.12.1

v0.12.2

v0.12.3

v0.12.4

v0.12.5

v0.12.6

v0.13.0

v0.13.1

v0.13.2

v0.13.3

v0.14.0

v0.14.1

v0.14.2

v0.14.3

v0.15.0

v0.15.1

v0.15.2

v0.15.3

v0.16.0

v0.16.1

v0.16.2

v0.16.3

v0.17.0

v0.17.1

v0.17.2

v0.17.3

v0.18.0

v0.18.1

v0.18.2

v0.18.3

v0.18.4

v0.18.5

v0.18.6

v0.18.7

v0.19.0

v0.2.0

v0.2.1

v0.2.2

v0.2.3

v0.2.4

v0.2.5

v0.2.6

v0.20.0

v0.20.1

v0.21.0

v0.22.0

v0.23.0

v0.23.1

v0.24.0

v0.25.0

v0.26.0

v0.27.0

v0.28.0

v0.29.0

v0.3.0

v0.3.1

v0.3.2

v0.3.3

v0.30.0

v0.30.1

v0.30.2

v0.31.0

v0.32.0

v0.33.0

v0.33.1

v0.34.0

v0.4.0

v0.4.1

v0.4.2

v0.5.0

v0.5.1

v0.5.10

v0.5.11

v0.5.12

v0.5.13

v0.5.2

v0.5.3

v0.5.4

v0.5.5

v0.5.6

v0.5.7

v0.5.8

v0.5.9

v0.6.0

v0.6.1

v0.6.2

v0.6.3

v0.6.4

v0.6.5

v0.6.6

v0.6.7

v0.7.0

v0.7.1

v0.7.10

v0.7.11

v0.7.12

v0.7.13

v0.7.14

v0.7.15

v0.7.16

v0.7.17

v0.7.18

v0.7.2

v0.7.3

v0.7.4

v0.7.5

v0.7.6

v0.7.7

v0.7.8

v0.7.9

v0.8.0

v0.8.1

v0.8.2

v0.8.3

v0.8.4

v0.8.5

v0.8.6

v0.8.7

v0.8.8

v0.8.9

v0.9.0

v0.9.1

v0.9.10

v0.9.2

v0.9.3

v0.9.4

v0.9.5

v0.9.6

v0.9.7

v0.9.8

v0.9.9

Database specific

vanir_signatures_modified

"2026-07-22T03:08:50Z"

vanir_signatures

[
    {
        "signature_type": "Function",
        "target": {
            "file": "httplib.h",
            "function": "read_content"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-29ab28dd",
        "signature_version": "v1",
        "digest": {
            "function_hash": "74746730314336700382392421616361087673",
            "length": 1376.0
        }
    },
    {
        "signature_type": "Function",
        "target": {
            "file": "httplib.h",
            "function": "Server::routing"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-797167f0",
        "signature_version": "v1",
        "digest": {
            "function_hash": "3569740634388511840270561711140388394",
            "length": 2190.0
        }
    },
    {
        "signature_type": "Function",
        "target": {
            "file": "httplib.h",
            "function": "prepare_content_receiver"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-9b30a385",
        "signature_version": "v1",
        "digest": {
            "function_hash": "27401325142482852988380135752401769151",
            "length": 924.0
        }
    },
    {
        "signature_type": "Line",
        "target": {
            "file": "httplib.h"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-bcea864b",
        "signature_version": "v1",
        "digest": {
            "line_hashes": [
                "336620093775998130083204534146315144902",
                "48261278978696573782838737954150987740",
                "25263993843790355181074608904646098856",
                "270565861836672539415351342119216784964",
                "307733686717758452394557357153091473703",
                "241423657130170861817757171211232425161",
                "277223009612079348722281460193068094464",
                "289645906111598587169901904179132149177",
                "288441847406440607085773995130574482900",
                "6154085008139808168913825350636784842",
                "254843035028795877504312647447110684640",
                "48100023920598998605003155898859628559",
                "61000319865907416719250901747454429058",
                "164609337165507433469985209426698622152",
                "323323656031063368219382194435717382538",
                "339885592849685253453127287063162146111",
                "229080025159869799351818857383716339213",
                "315596621814371842598799807411962157247",
                "299917188554656618663061553949547970981",
                "298801253700645922171765926966072659129",
                "24172106091241432159952864198178353426",
                "698028545424733854233987376183115324",
                "83842166720811206405484969212492004838",
                "79548144836350619236071304504736482096",
                "274222254423662415877052249091548526598",
                "274065380976258011280917651245620557561",
                "309819496877884115803626941510040776953",
                "170138664843069500949910245824311119350",
                "227414381486183759363930604017565111540",
                "246584266086112446949006322472394906663",
                "61114654632616001000626608648672254879",
                "295885261486842304824203782371919549249",
                "131809600914814201549906272221481473991",
                "60637104013833694847248289859978752876",
                "253307259574145663736606345047614567188",
                "234472319674310582768617042425634500812",
                "57909769051648067177424741902096300191",
                "229854370268696068680560460278661675998",
                "329748775302257267944651610129827526663",
                "7597105729796335360767048818985228252",
                "150938064528720896682108233729733324695",
                "259634372513854527504924369745077623030",
                "88555999646887882443298128630321814354",
                "133103455409917410925821273976952262082",
                "182661680406452625961725031580022317777",
                "47169067705431600468176616088221256930",
                "153875378108037217357820481687654368032",
                "257709864409495343765777771396199601810",
                "163729283931957104749321934314328942761",
                "139785599167853663183507136896951074467",
                "312444211110648884581367336570039970070",
                "233603659413596956999586450613374146592",
                "156962228014884729667527118855238316490",
                "101009091887649194001364542811491840217",
                "197040198173911966444105035093462691291",
                "199777601485856131570416260161335561920",
                "117034669642092749885021784003669868720",
                "136618464789765519394256895721515826112",
                "161809727313611182309148393775525695883",
                "118899281503478189466977023624133197343",
                "260412467073191681294758342173702895970",
                "331506801141463152245080050964869645059",
                "76342194727321959629312426244182888009",
                "223806271234802523021061016499458327744",
                "180268995372409327452520676763574733498"
            ],
            "threshold": 0.9
        }
    },
    {
        "signature_type": "Line",
        "target": {
            "file": "test/test.cc"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-db2566d3",
        "signature_version": "v1",
        "digest": {
            "line_hashes": [
                "314258632294440309735684983878683059517",
                "21214091782338116108085564081410487219",
                "324856385457370040346550676230505883529",
                "254161945597284604992433239876287001107",
                "114599813364296555088160024051460464000",
                "11818806752357983553704969358398234908",
                "230574403061835867794759007349882061150"
            ],
            "threshold": 0.9
        }
    },
    {
        "signature_type": "Function",
        "target": {
            "file": "test/test.cc",
            "function": "TEST"
        },
        "deprecated": false,
        "source": "https://github.com/yhirose/cpp-httplib/commit/c99d7472b5cf4869d3897b9afc9792063a3d15a8",
        "id": "CVE-2026-28435-de877a74",
        "signature_version": "v1",
        "digest": {
            "function_hash": "322006012403534972482415604374091314249",
            "length": 995.0
        }
    }
]

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-28435.json"